Resultant Wind Direction is measured in degrees compass.
Resultant wind direction values are obtained by converting the 5-minute wind speeds and directions for the hour into a single hourly vector. Resultant wind direction is the direction of this vector. Wind direction, the direction from which the wind is blowing, is measured to the nearest degree based on a 360 degree compass with 360 degrees being from the North and 180 degrees being from the South. Zero degrees means the winds are calm.